Reduced gauge bottle cap

ABSTRACT

A reduced gauged crown for a container opening includes a corrugated panel portion such that the corrugation strengthens the crown material and allows less material to be used for the crown than would be used for an uncorrugated bottle cap.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure is a continuation of U.S. patent applicationentitled “Reduced Gauge Bottle Cap” filed May 5, 2017, and assigned Ser.No. 15/588,263, which is a continuation of Ser. No. 14/243,437, filedJul. 24, 2012.

FIELD OF THE DISCLOSURE

The present disclosure relates to caps and crowns for beverage bottlesand other containers, and in particular, to a reduced gauge corrugatedbottle cap.

BACKGROUND

Published U.S. patent application Ser. No. 12/597,385 to MerinoCaballero (“Caballero”) discloses a low gauge crown cap in which the toppanel exhibits grooves in various shapes, depending on the embodiment,to achieve corrugation and obtain a crown that has a low gauge of crownmaterial such as steel. Although not prior art due a priority datesubsequent to the priority date of the present disclosure, the presentinventor acknowledges the Caballero application because it was publishedprior to the filing date of the present disclosure.

Related application Ser. No. 12/903,533, and its parent Ser. No.11/698,247 (issued as U.S. Pat. No. 8,061,544), referenced above,disclose a bottle crown that has a seat in which rests a pull tabassembly so that the pull tab assembly is flush with the top of thecrown. The seat is formed by means of a depression or recess in the topof the crown. A benefit of the recessed top is that the recessfunctionally acts to corrugate the top of the crown. As is wellunderstood, corrugation has the advantage of stiffening a sheet ofmaterial against forces that are perpendicular to the direction ofcorrugation. That is, a corrugated sheet is harder to bend than anon-corrugated sheet, at least in certain directions. A bottle crownthat has corrugation across its top will be stiffer than anon-corrugated crown. Therefore, to achieve the same degree of stiffnessof a non-corrugated crown, a corrugated crown may be thinner, or have alower gauge, of crown material such as steel or tinplate. The advantagesof corrugation that are implicitly inherent in the crown of the '533application are made explicit in the present disclosure. The presentdisclosure, therefore, describes a corrugated crown and the advantagesthereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description that follows, by way of non-limiting examplesof embodiments, makes reference to the noted drawings in which referencenumerals represent the same parts throughout the several views of thedrawings, and in which:

FIG. 1 is an isometric side view illustration of a reduced gauge crownof the present invention.

FIG. 2A is a top view illustration of the crown of FIG. 1.

FIG. 2B is a side cross-section view of the crown of FIG. 2A.

FIG. 3A is a top view illustration of an alternative embodiment of acrown of the present disclosure.

FIG. 3B is a side cross-section view of the crown of FIG. 3A.

FIG. 4A is a top view illustration of another alternative embodiment ofa crown of the present disclosure.

FIG. 4B is a side cross-section view of the crown of FIG. 4A.

FIG. 5 is an isometric side view illustration of another embodiment of areduced gauge crown of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1 is an isometric side view illustration of a reduced gauge crownof the present invention. Crown 100 includes top portion 110 contiguouswith recess 120 which terminates in panel 130. Skirt 140 downwardlyextends from top 110. In some specific embodiments a flange extendsobliquely from skirt 140. Alternating flutes 150 and lands 152 areformed on a circumferential portion of skirt 140. Crown 100, and othercrowns shown in the figures, is shown as a pry-off type that is openedwith a lever. The present invention also encompasses a twist-off type(not shown in the figures) that is opened by twisting, as will beunderstood by persons familiar with crown cap technology. Finally, crown100 is suitable for use with pull tab type assemblies mounted to panel130 with effective score lines embossed on crown 100. Such an embodimentof the crown 100 configured for use with such a pull tab is discussedbelow with reference to FIG. 5.

Panel 130 is recessed, that is, it is lower than top 110 but iscontiguous with top 110 by virtue of transition surface 120, which willbe referred to herein for convenience as recess 120. Recess 120 mayformed in crown 100 in a variety of suitable way to provide advantageousshapes. For example, in specific exemplary embodiments concentric tiers,grooves or steps are integrally formed in the crown 100 material untilthe desired depth of panel 130 is obtained, as illustrated in FIG. 1. Inalternative embodiments, recess 120 is formed with a smoothly curvedsurface from top 110 to panel 130. The form of recess 120 functions asribs or structural reinforcements that, it is surmised, help to stiffenpanel 130 against deflection or deformation.

Skirt 140 descends from top 110 along the external perimeter of crown100 and in specific exemplary embodiments smoothly merges intodownwardly and radially outwardly extending flange. The skirt 140 ispreferably adapted to be crimped onto the neck of a bottle for sealing.Specific exemplary embodiments of skirt 140 are divided into undulating,repeating portions that define the flutes 150 and lands 152. Preferably,the repeating portions are circumferentially evenly spaced apart suchthat each flute 150 is identical to all other flutes 150 around thecircumference of the crown cap 100, and each land 152 is identical toall other lands 152 around the circumference of the crown cap 100. Itshould be understood that the crown cap 100 may include any number offlutes 150 and lands 152.

Referring to now to FIGS. 2A and 2B, 3A and 3B and 4A and 4B, the “B”figure of each depicted embodiment is the horizontal cross section ofits “A” counterpart through line B-B. Each embodiment, designated 2A/B,3A/B and 4A/B, is characterized by a particular diameter of its panel130, as represented by width B 210, 310 and 410 of each embodiment,respectively, and depth A of recess 120 represented by depths 220, 320,and 420, respectively.

A specific amount of material strengthening from corrugation is achievedby selecting an embodiment with a particular combination of paneldiameter 210, 310 or 410, for example, and recess depth 220, 320 or 420,for example. Exemplary embodiment 2A/B, for instance, has panel diameter210, which is relatively wide, and recess depth 220, which isintermediately deep. Exemplary embodiment 3A/B has panel width 310,which of intermediate width, and recess depth 320, which is the deepestof the three exemplary embodiments. Exemplary embodiment 4A/B has paneldiameter 410, which is the narrowest of the embodiments, and recessdepth 420, which is the shallowest depth of the three embodiments. Toobtain a desired amount of material strengthening from corrugation, acombination of panel width 210, 310, or 410, for example, and recessdepth 220, 320 or 420, for example, is selected to achieve a specificembodiment.

Corrugation strengthens materials. This is particularly true of laminarmaterials formed into a sheet or plane. A laminar product can use lessof a material if the material is corrugated to provide lateral strength.A bottle cap is a laminar product in which the sheet material, oftensteel or tin plate, is shaped to be affixed to the top of a bottle orother container. A standard pry-off or twist off cap has a thickness ofmaterial that is predominantly determined by considerations of leakprevention and the secureness of the attachment of the cap to thecontainer.

Billions of bottle caps are used worldwide and the cost of the caps islargely determined by the amount of material required for the caps.Corrugation allows caps that use less material to have the equivalentstrength of a standard thick crown, a corrugated crown is thinner, thatis, it has a reduced gauge, in comparison to a standard bottle cap. Anadvantage of a reduced gauge cap is the money savings obtained by usingless material.

Another advantage of a reduced gauge corrugated cap comes into play withinnovated “pull-off” caps, which have a pull tab assembly attached tothe crown as described in the related patent applications, oneembodiment of which is described in detail below with reference to FIG.5. As discussed below, the pull tab breaks the cap material and thecrown is torn off the bottle using the pull tab. A reduced gauge capfacilitates the tear off because the cap material is thin and thetearing action is parallel to the direction of material strengtheningprovided by the corrugation and therefor the tearing force does not haveto overcome the material strengthening of the corrugation. Corrugationaffords material strengthening perpendicular to the direction ofcorrugation.

In addition to the structures illustrated in the figures herein, it isunderstood that other structures will imbue a cap of the presentdisclosure with the advantages of corrugation and provide a reducedgauge crown for a bottle. For instance, concentric rings, which progressfrom the top of the skirt toward the center of the panel, and decorativeshapes such as stars, brand logos, sports team logos, religiousinsignia, and the like, formed in the plane of the cap, are embraced inthe present disclosure.

Corrugation forms may be provided to a bottle cap by a variety means,including without limitation, metal stamping, pressing, embossing and soforth. Non-metal crowns of the present disclosure may be formed byinjection molding for plastic crowns, or by other suitable means ofproduction.

The crown caps 100 preferably are formed with steel of increasedhardness compared with conventional crown caps presently in commercialproduction. For example, conventional crown caps are often formed ofsingle reduced, T4, tinplate having a thickness of from 0.21 mm to 0.23mm. Such tinplate has an average hardness (that is, the reportedhardness value regardless of +/−variations) of approximately 61 on a 30T hardness scale, in accordance with ASTM 623. Crown caps 100 describedherein may be made thinner and lighter weight compared, with the priorart, for example, crown caps 100 may be formed of a material having athickness of about 0.16 mm to 0.18 mm that have the same or roughlyequal performance as conventional, thicker caps. These decreases inmetal usage are more easily achieved when the structure of crown caps 10are made with steel having increased hardness. For example, the inventorhas demonstrated the effectiveness of low gauge crowns having groovesusing DR8 (according to ASTM 623) or DR550 (according to EN 10203).Optionally, the inventor surmises that other materials may be used, suchas single reduced tinplate or like material having enhance tempering,tin-free steel having similar properties as those described herein, andthe like.

The crown caps 100 preferably have an average hardness of greater than62 on the 30 T scale (conforming to ASTM 623), more preferably greaterthan about 65, more preferably greater than about 68, more preferablygreater than about 71. The embodiments shown in FIG. 1 and FIG. 3A weredemonstrated to be effective using steel having a hardness of 73. Theupper limit of hardness is set by the maximum stress acceptable to theglass bottle during the crimping process or the spring back (which maytend to urge the crimped flanges toward an uncrimped state) associatedwith harder plate.

The crown caps 100 may be formed with conventional press equipment, withonly minor changes to parts of the tooling to form the structure (suchas the grooves, crosses, stars, and dimples). And crown caps 100 may becrimped with conventional equipment, only modified to have a smallerthroat compared with existing, conventional crimpers.

Because hardness has a relationship to strength as reflected in theyield point, the aspect of the hardness of the crown may be expressed inyield point on a corresponding scale. For example, DR8 or DR550 tinplatemay has a yield point (in a tensile test) of 550 MFA. The inventorbelieves that the most advantageous crown cap has a combination of oneor more of the structured described herein and harder plate as describedherein. A crown of the present disclosure, however, encompasses crowncaps that do not have all of the structure, materials, and/or advantagesin this specification.

According to this description, commercially acceptable crown caps formedaccording to the present disclosure can be commercially made with up to25 percent less steel compared with many conventional crown caps, whichhas corresponding advantages in carbon emissions. The savings in steelweight are approximately proportionate to the reduction in metalthickness. Further, even though energy required to cool an individualcrown is tiny, the energy required to cool the total number of crownsproduced each year (approximately 45 billion, in North America andapproximately 300 billion throughout the world) and the correspondingreduction in that energy, it significant.

In addition to the various structures described herein, certainadvantages over the prior art are bestowed on the present crown by therecommended specifications shown in Table 1.

TABLE 1 Items Acceptable Range/Target_(—) 1. Appearance Disc properlyadhering White liner Complete liner Clean liner Clean crown and ring Norust and scratch for crown and ring Two cut lines on the downwardsurface of crown Rivet Crown 2. Dimensions Thickness (mm): 0.16-0.18Inside diameter (mm): 32.08-32.12 Outside diameter (mm): 26.60-26.90Radius of angle (mm): 1.5-1.9 Number of angles: 21 Ring Diameter (mm):21.1-21.5 Thickness (mm): 0.28-0.32 Liner Diameter (mm): 20.00-20.50 3.Rockwell Hardness T4 on the Rockwell 30T scale 4. Secure Seal Greaterthan/equal to 150 PSI for 1 minute 5. Finish Hardness Should not scratchwith “H” pencil 6. Sensory No significant differences with an identifiedcontrol after 12 weeks at 20 degrees C. 7. Lubricant Migration Noparticles or lubricant should be present 8. Simulated Palletizing CO2loss should not differ against control caps when stored for 1 week withmax weight of 45 Kgs over each bottle 9. Corrosion Maximum corrosion:slight to moderate 10. Odor No off odors detected 11. Pulling Force 2.5kg of Ring (kg) 12. Composition of Tinplate crown and ring; food classnon-PVC Material for liner 13. Package 5000 Crowns per box 14. Pressure(kg) 10 kg 15. Container Loading 1,000 Master Cartons 16. PrintingLogo/other design may be printed on the Easy Pull ™ Cap 17. CrownAnti-Oxidation Material used is “food grade” PET; clear, with no odor,1.2 UM (micrometers)

In particular, a tinplate material which, demonstrates an approximatehardness of T-4 on the Rockwell 30 T Hardness Scale is preferred for thepresent cap (see item 3 in table 1). This may be contrasted against theprior art which typically uses tinplate having a hardness of K-3 on theRockwell scale. The preferred softer tinplate material requires lessforce to open and tear with the opener assembly of the present crownwhile still providing sufficient sealing of the container contents. Forthe purposes of this disclosure, tinplate refers the any material,including tin or tin alloys, from which a crown may be fabricated anddoes not necessarily mean that the crown is made from tin or a tinalloy.

FIG. 5 is an isometric side view illustration of another embodiment of areduced gauge crown 500 of the present invention. This embodiment of areduced gauge crown is configured for use with pull tab type assembliesmounted to the top panel 530. The pull tab apparatus is not shown inorder to illustrate more plainly the cut lines 6 d and 6 e. In apreferred embodiment, one of the cut lines 6 e provides an S-curve ortail segment 6 f that extends along the skirt 540 of crown 500. S-curve6 f may facilitate the removal of crown 500 from a container opening. Inoperation, a person tears from center 550 along cut lines 6 d and 6 e.When the tear reaches S-curve 6 f, the tearing force follows the S-curveaway from cut line 6 d and impels the tear along cut line 6 d toterminus 560 which breaks open crown 500. Continued tearing force alongS-curve 6 f pulls skirt 540 away from the container opening (not shown)and releases crown 500 from the container (not shown). Another featureillustrated in FIG. 5 is one or more spoilage indicators 570 such asdimples depressed in crown 500 and positioned so as not to be obscuredby the pull ring apparatus of the present disclosure. For containersthat are vacuum sealed, spoilage indicators 570 pop up in the event thatthe pressure seal is lost. One or more circular depressions 580 createspace in the top 530 of crown 500 to seat the pull ring and the rest ofthe opener apparatus. Seat 580 is of sufficient depth that pull ring issubstantially flush with the top 530 of crown 500. Such an embodimentadvantageously is suitable for use in conventional bottle cappingmachines without having to retool or refit the machine.

The foregoing description is provided for the purpose of explanation andis not to be construed as limiting the invention. While the inventionhas been described with reference to preferred embodiments or preferredmethods, it is understood that the words which have been used herein arewords of description and illustration, rather than words of limitation.Furthermore, although the invention has been described herein withreference to particular structure, methods, and embodiments, theinvention is not intended to be limited to the particulars disclosedherein, as the invention extends to all structures, methods and usesthat are within the scope of the appended claims. Those skilled in therelevant art, having the benefit of the teachings of this specification,may effect numerous modifications to the invention as described herein,and changes may be made without departing from the scope and spirit ofthe invention as defined by the appended claims. Furthermore, anyfeatures of one described embodiment can be applicable to the otherembodiments described herein.

Such embodiments of the inventive subject matter may be referred toherein, individually and/or collectively, by the term “invention” merelyfor convenience and without intending to voluntarily limit the scope ofthis application to any single invention or inventive concept if morethan one is in fact disclosed. Thus, although specific embodiments havebeen illustrated and described herein, it should be appreciated that anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

In summary, the present disclosure describes a crown for a containeropening. The crown has a top portion and an inner portion contiguouswith the top portion. The inner is portion formed into a panel. An outerportion contiguous with the top portion is formed into a skirt thatdescends from the top portion. The crown has corrugation formed in thepanel.

The present disclosure also contemplates methods for making the crowndescribed above. Methods include the steps of shaping a sheet of crownmaterial to provide a top portion and an inner portion contiguous withthe top portion and formed into a panel. An outer portion contiguouswith the top portion is formed into a skirt that descends from the topportion. The methods also include forming corrugation in the panel.

In specific embodiments the step of forming corrugation in the panelconsists of forming a recess that descends from the top portion to thepanel in the inner portion.

The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the claims reflect,inventive subject matter lies in less than all features of a singledisclosed embodiment. Thus the following claims are hereby incorporatedinto the Detailed Description, with each claim standing on its own as aseparate embodiment.

The description has made reference to several exemplary embodiments. Itis understood, however, that the words that have been used are words ofdescription and illustration, rather than words of limitation. Changesmay be made within the purview of the appended claims, as presentlystated and as amended, without departing from the scope and spirit ofthe disclosure in all its aspects. Although description makes referenceto particular means, materials and embodiments, the disclosure is notintended to be limited to the particulars disclosed; rather, thedisclosure extends to all functionally equivalent technologies,structures, methods and uses such as are within the scope of theappended claims.

What is claimed is:
 1. A reduced gauge crown for a pressurized containeropening, the crown comprising: a top portion, an inner portioncontiguous with the top portion, an outer portion contiguous with thetop portion, the outer portion being formed into an annular skirt thatdescends from the top portion, CHARACTERIZED IN THAT: the inner portioncomprises a central portion comprising a recessed panel; and the crownhas a thickness gauge in the range of 0.16 mm to 0.18 mm, and materialcomprising the crown has an average hardness of greater than 62 on a 30T hardness scale but less than an upper limit of hardness set by themaximum stress acceptable to the container during a crimping process orthe spring back associated with a harder material; wherein the recessedpanel comprises a uniform thickness across its entirety, and is parallelwith the top portion but positioned entirely below a bottom surface ofthe top portion, the central portion comprising a concentric downwardformed curved transition surface contiguously connecting the top portionand the recessed panel, the transition surface and recessed paneltogether stiffening the inner portion by providing materialstrengthening perpendicular to the direction of the downward formedrecessed panel.
 2. The crown of claim 1, wherein material comprising thecrown has an average hardness of greater than 65 on the 30 T hardnessscale.
 3. The crown of claim 1, wherein material comprising the crownhas an average hardness of greater than 68 on the 30 T hardness scale.4. The crown of claim 1, wherein material comprising the crown has anaverage hardness of greater than 71 on the 30 T hardness scale.
 5. Thecrown of claim 1, wherein material comprising the crown has an averagehardness of greater than 73 on the 30 T hardness scale.
 6. The crown ofclaim 1, wherein the transition surface and recessed panel togetherprovide material strengthening substantially equal to materialstrengthening provided by a crown without the central portion, andhaving a thickness gauge in the range of 0.21 mm to 0.23 mm andcomprising material having an average hardness of approximately 61 onthe 30 T hardness scale.
 7. The crown of claim 1, wherein the transitionsurface comprises a plurality of concave concentric rings formeddownward into the top portion that progress from the a top of the skirttoward a center of the crown.
 8. The crown of claim 1, wherein thetransition surface comprises a plurality of concave circular depressionsformed downward into the top portion that progress from the a top of theskirt toward a center of the crown.
 9. A method for making a reducedgauge crown for a pressurized container, the method comprising: shapinga sheet of crown material to provide a top portion, an inner portioncontiguous with the top portion, and an outer portion contiguous withthe top portion and formed into an annular skirt that descends from thetop portion; CHARACTERIZED IN THAT the method further comprises:employing crown material having a thickness gauge in the range of 0.16mm to 0.18 mm, and having an average hardness of greater than 62 on a 30T hardness scale; forming the inner portion into a central portioncomprising a recessed panel having a uniform thickness across itsentirety, and is parallel with the top portion but positioned entirelybelow a bottom surface of the top portion; and forming the centralportion by downwardly forming a concentric curved transition surfacecontiguously connecting the top portion and the recessed panel such thatthe transition surface and recessed panel together stiffen the innerportion by providing material strengthening perpendicular to thedirection of the downward formed recessed panel.
 10. The method of claim9, wherein material comprising the crown has an average hardness ofgreater than 65 on the 30 T hardness scale.
 11. The method of claim 9,wherein material comprising the crown has an average hardness of greaterthan 68 on the 30 T hardness scale.
 12. The method of claim 9, whereinmaterial comprising the crown has an average hardness of greater than 71on the 30 T hardness scale.
 13. The method of claim 9, wherein materialcomprising the crown has an average hardness of greater than 73 on the30 T hardness scale.
 14. The method of claim 9, wherein the transitionsurface and recessed panel together provide material strengtheningsubstantially equal to material strengthening provided by a crownwithout the central portion, and having a thickness gauge in the rangeof 0.21 mm to 0.23 mm and comprising material having an average hardnessof approximately 61 on the 30 T hardness scale.
 15. The method of claim9, wherein the transition surface comprises a plurality of concaveconcentric rings formed downward into the top portion to descendingdepths that progress from the skirt toward a center of the crown. 16.The crown of claim 9, wherein the transition surface comprises aplurality of concave circular depressions formed downward into the topportion that progress from the a top of the skirt toward a center of thecrown.